This invention relates to bearings. More particularly, this invention is a combination of elements including a temperature sensor to monitor temperature conditions within the bearing, an electric-acoustic transducer to convert signals representing the temperature into acoustic waves and an acoustic-electric transducer to receive the acoustic waves and convert the acoustic waves into electric signals and an electronic system for displaying information representing the temperatures inside the bearing.
There are numerous bearing applications where the bearing is mounted in a housing that denies access to the bearing by servicing personnel. For example, one characteristic which indicates how the bearing is performing is the temperature characteristics within the bearing. The temperature characteristics are best measured from inside the bearing. Temperature-measurement sensors are more responsive the closer they are to the source of heat generation. A more reliable measurement is obtained if the temperature sensor is permanently mounted within the bearing eliminating installation differences and misapplication of the temperature sensor.
Furthermore, in applications where the bearing is transferred to a number of different locations during its life, the ability to maintain the historical data pertaining to an individual bearing is of great advantage in diagnosing bearing conditions.
While better measurements are obtained from within the bearing, the information must be made available to the personnel responsible for servicing the bearing for this information to be useful in diagnosing problems occurring in the bearing and surrounding equipment. Therefore, only if a system can be devised which can relay temperature information out of the bearing will a measurement taken inside the bearing be of value.
Currently known systems for indicating the temperature inside a bearing require that the transfer of information from within the bearing are obtained by hard-wired electrical connections. That is, wires are required which are connected to a transducer used as a receiver of information, then the wires lead through holes in the housing in which the bearing is mounted and finally the wires lead to a receiving transducer outside the housing where the signals are treated electronically for display. This is unwieldy in temperature applications where the bearings are very large and are removed and returned to service frequently, such as, in steel rolling mills. For these applications, clearly a system which transfers information such as temperature from within the bearing to outside the housing in which the bearing is mounted without the use of wires for the transfer is of great value. This invention provides such a system. No hard wires are used for transmitting temperature information from the bearing within the housing to a receiver located on the outside of housing.
The foregoing illustrates limitations known to exist in present devices and methods. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.